Thornton Quarry (Thornton, Illinois)

USA / Illinois / Thornton / Thornton, Illinois
 industrial area, quarry, reef, limestone quarry
Thornton Quarry is one of the largest quarries in the world, measuring 1.5 miles (2.5 km) long, 0.5 miles (1 km) wide, and 400 feet (125 m) deep.

The quarried stone is at the heart of a roughly 430 million year old [Silurian] tropical reef. A layer of this Silurian Dolomite underlies much of the Chicago area and represents the lithified remnants of carbonaceous sediments which accumulated on the slopes of the ancient continental core. This continental core is now essentially seen at the surface as granitic and other hard rocks in the upper peninsula of Michigan as well as Canada.

One may find the fossilized remains of organisms that once lived on or near this once enormous atoll or seamount reef. The continental masses, some 40km thick, drift over the surface of the Earth over periods of millions of years. This region of the Earth's crust was then located within the tropics.

The quarry is now part of the TARP system in Chicago which manages stormwater runoff from the Chicago sewer system.

www.pitandquarry.com/how-a-section-of-the-thornton-quar...

en.wikipedia.org/wiki/Silurian
en.wikipedia.org/wiki/Niagara_Escarpment
Wikipedia article: http://en.wikipedia.org/wiki/Thornton_Quarry
Nearby cities:
Coordinates:   41°34'15"N   87°37'27"W

Comments

  • Anyone passing by on Rt 294 in a tall vehicle (truck or RV) can get an amazing view of this quarry.
This article was last modified 4 years ago